Process for the manufacture of anthraquinone



UNITED STATES P A T E coUE'rNEY co ovEE, or PHILADELPHIA, PENNSYLVANIA, ANL HARRY 1). GIBBS, or

sAN FRANCISCO, CALIFORNIA; SAID CONOVER AssieNoR T0 JAMES M. SELDEN,

OF PITTSBURGH, PENNSYLVANIA.

PROCESS FOR THE MANUFACTURE OF ANTHRAQUINONE.

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No Drawing.

Specification of Letters Patent. Pat nted ltflay 23 1922 Application filed June 7,

1917. Serial No. 173,404.

(FILED UNDER'THE ACT OF MARCH 3, 1883, 22 S TAT. L, 625.)

To all whom it may concern Be it known that we, COURTNEY CoNovER and HARRY D. GIBBS, citizens of the United States of America and employees of the De-.

partment of Agriculture, residing in the city of Philadelphia, county of Philadelphla, State of Pennsylvania, and in the city of San Francisco, county of San Francisco, State of California, respectively, (whose post-office address is Washington, District of Columbia,) have invented a new and useful Process for the Manufacture of Anthraquinone.

This application is made under the act of March 3, 1883, chapter 143 (22 Stat, 625),

and the invention herein described and claimed. maybe used by the Government of the United Statesor any of its ofiicers or employees in the prosecution of work for the Government, or any person in the United States, without payment to us of, any royalty.

Our invention relates to a process for the manufacture of anthraquinone from anthracene.

It is well known that anthraq uinone is commonly produced by the oxidation ofans thracene in an extremely fine state of ,divi sion by means of chromic acid] In this process'the reduction of the anthracene to the fine state of division is difficult and expensive, and further the chromic-acid subsequently used for oxidation is a costly reagent. The object of our invention s to provide a process for the manufacture of anthraquinone which will be free from the objectionable features of the processes employed Our inventlo'n consists in the production of anthraquinone from anthracene by heating the anthracene until it passes into the vapor phase, mixing this anthracene vapor with an oxygen-containing gas -mixture, forcing this mixture of gases into close contact with finely divided oxidesof vanadium, heated v .to a' temperature ranging from 250 C. to

650 (1., under which treatment the anthra cone is partially oxidized to form the valuable product named.

To illustrate the practical operation of .our process we shall describe in detail the preferred procedure. Anthracene is melted and is caused to flow continuously at a measreaction products may ured rate into a heated chamber where it is volatilized. This vapor of anthracene is then mixed with air in excess of the proportion theoretically required to oxidize anthracene to anthraquinone. The mixture of air and anthracene vapor is passed into a reaction chamber maintained at a temperature ranging from 350 to 550 C., the preferred temperature being 500 C. In this chamber the gas mixture is forced into close contact with oxides of vanadium in the form of a fine powder. This powder is supported on trays or on a porous material where, by mechanical means the current of mixed gases is forced through it.' The gases are kept .under pressure only sufiicientto cause them We have discovered that the process as, above described may be varied in many ways and yet will produce anthraquinone. Thus, oxygen maybe substituted wholly or in part for air, or air may be mixed with a gas which is relatively inert under-'the-conditions ob taining in the process. The oxides of vanadium may be mixed with or combined with other substances, such as other metallic oxides, or with asbestos, pumice stone, or other materials. The gas mixture may be brought in contact with or forced through the'catalyst in many different waysf The proportion of anthracene vapor to the oxygen-containing gas mixture may be variedwithin wide limits. Materials containing anthracene, together with the substances commonly associated with it may be used instead .of pure anthracene. And the be separated by various well-known means.

Having thus described our.invention, we claim- 1.. The method of oxidizing anthracene, which comprises subjecting anthracene in the vapor phase to oxidation by oxygen in the presence of an oxid of'vanadium as a catalyzer, at a temperature of about 300 C. to 500 C. f e

2. The method 0f oxidizing anthracene,

which comprises passing a mixture of an tures in the presence of two subscribing wit- .thracene in the vapor phase, and an oxygen nesses.

containing gas into contact with an oxid of COURTNEY CONOVER. vanadium as acatalyzei' heated to a tempera- HARRY D. GIBBS. ture of about 300 C. to 500 0. whereby an- Witnesses: thraquinone is produced. PHILIP L. GoWEN, In testimony whereof, we afiix' our signa- R. R. WILLIAMS. 

